Steam-boiler.



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Patented Sept. 5, I899. 0. C. PECK.

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(Appliqation filed Apr. 25, 1898.) I (No Model.) 5 Sheets$hea't 2.

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Patented Sept. 5, I899.

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C G PECK STEAM BOILER.

(Application filed Apr. 25, 1898.)

(No Model.)

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Patented Sept. 5, I899. C. C. PECK.

STEAM BOILER.

(Application filed Apr. 25', 1898.)

(No Model.)

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No. 632,277. Patented se t; 5, I899.

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(Application filed Apr. 25, 1898.) (No Model.) 57Sheets-Sheet 5.

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NME T STEAM BOlLER.

SPECIFICATION forming part of Letters Patent No. 632,277, dated September 5, 1899.

Application filed April 2 5, 1 8 9 8.

To aZZ whom it may concern.-

Be it known that I, OAssIUs CARROLL PECK, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Steam- Boilers, of which the following is a specification suificient to enable others skilled in the art to which the invention appertains to make and use the same.

My invention relates to the class of steamboilers known as horizontal return tubular boilers, and is equally applicable to externally-fired boilers and to boilers having internal furnaces.

The main object of my invention isto improve boiler efficiency, but it also includes the attainment of good proportions of waterspace, steam-space, and water-separating surface for steam, whereby easy action of the boiler, good reserve power, and dry steam are insured. These results are attain ed by dividing the fire-tubes into two nearly equal divisions and constructing the boiler and setting in such manner that the fire-gases first pass from the furnace through the flame-passage to the rear end of boiler and thence by one set of fire-tubes to the front end of boiler and by another set of tubes to the rear end, where they escape to chimney. The fire-gases thus traverse the length of boiler three times and in such manner as to bring down their temperature before escape to chimney as low as is practicable in a boiler structure consisting of a single shell. At the same time the necessary proportions of area through tubes to give proper draft and of diameter of shell to contain the necessary number of well-spaced tubes of good length gives to the boiler structure more than the usual allowance of heating-surface, water-space, steam-space, and Water-separating surface for escape of steam. In the case of boilers provided with internal furnaces, such as the much-used Scotch style of boiler, the proportions of the boiler structure can be reduced and economy promoted by the use of an inducing-fan to create requisite draft and allow of the use of smaller and shorter tubes than could be employed with natural draft. In order to make the Whole boiler outfit compact and self-contained and prevent escape of heat into the boiler-room, I extend the rear end of boiler-chamber to work of side walls.

Serial No- 678,817. (No model.)

.therest of the shell is covered.

In the accompanying drawings, Figure I is a front end elevation of an externally-fired boiler, showing one-half of the castings of flue-doors and furnace-front, together with brickwork, the other half of drawing showing said fronts removed to reveal one-half of the boiler-head and a cross-section of brick- Fig. II is a lengthwise vertical central section of same boiler with brickwork setting. Fig. III is a front end elevation of a boiler with internal furnace,

showing on one side of the vertical central line the cast front of furnace and the fluedoor and on the other side of said line onehalf the front head of boiler. Fig. IV is a rear end elevation of same boiler, showing on one side of the vertical central line one-half of the door which opens into the fan-chamber and on the other side of said line part of fancasing and engine-casing, the position of fan being indicated by dotted or broken lines. Fig. V is a lengthwise vertical central section of same boiler and fan-chamber, with edge view of fan-casing and side of engine-casing shown in elevation. Fig. V1 is a rear end elevation of same style of boiler as constructed for use with natural draft, and Fig. VII is a Vertical central lengthwise section of rear end of same boiler.

A is the boiler, having an upperset of tubes at and a lower set a and a dry-pipe a B is the furnace at front end, and O the combustion-chamber at rear end, of boiler.

In Figs. III, IV, and V, D is a fan-chamber formed by an extension of the boilershell, and F is a fan for inducing sufficient draft through the fire and the boiler to operate lthe latter.

In Figs. I and II, G is a sediment-trough for collecting and retaining solid matter deposited from the feed-Water. The upper portion of shell A, Fig. II, is extended at the rear end to form a smoke-box G II is the feed-pipe,

which delivers feed-water into the troughG, and I the blow-off pipe, 0. the steam-nozzle, and a the safety-valve nozzles. course of the fire-cases.

The operation of the boiler is as follows: Fire being started in furnace B through the Arrows show action of chimney-draft or of draft created by the inducing-fan F the gases and smoke are drawn either under the shell in case of the externally'fired boiler shown in Figs. I and II or through the furnace-flue b of the internally-fired boiler shown in Figs. III, IV, V, VI, and VII, and on reaching and passing through to rear-end combnstion-chamber 0 enter and pass through the lower set of tubes a to the front-end smoke-box G, whence they enter the upper set of tubes a and are thus conducted to the rear smoke-box 0 passing thence to the chimney or to the fan, as the case may be. The water-level J being maintained at the usual height of a few inches above tubes at, both sets of tubes are submerged, and the upper set having the least depth of submergen'ce the circulation of water and escape of steam are freest around and from these tubes, which condition tends to abstract heat most efficiently from the gases in their passage through the upper set of tubes, and thus bring their temperature down as low as is practicable in a single-shell boiler.

The tubes at and a may both be of same size, or they may differ in size, but in any case are so proportioned (diameter as compared with length) that the gases shall be cooled as much in passing through the two sets of tubes as is consistent with maintaining the required amount of boiler capacity. Thus in the boiler shown in Figs. II and III, which are working plans for a one-hundred-and-fifty-horse-power boiler designed to suit natural draft, the shell is seventy-eight inches in diameter, the tubes are four inches in diameter and sixteen feet long, and the number of tubes in set a is fortyeight and in set a the same number. These proportions give sufficient area through the tubes for the passage of gases for burning with an ordinary good chimney suiiicient coal to develop considerably more than the rating of the boiler, and the length of passage through the tubes being thirty-two feet for the two set-s of tubes is sufficient to cool said gases to a lower point than is possible with any return tubular boiler in which the gases go through the boiler but once, the same or equally good conditions of draft and similarly good proportions of heating-surface, steam and water space, and water-separating surface for steam being maintained.

In case of the boiler with internal furnace shown in Figs. III, IV, V, VI, and VII, which is of the same rating as the externally-fired boiler to obtain similarly good proportions with three-inch tubes,the length of these tubes is made twelve feet, the number in set a being eighty-two and in set a ninety.

The effect of the front-end smoke-chamber O in mixing the gases as they pass from the upper to the lower set of tubes is in the direction of securing more complete absorption of their heat by the boiler-water than if they flowed continuously through one set of tubes having the same heating-surface as the two sets a. and a.

As the internal operation of the boiler does not differ essentially from that of other return tubular boilers, it is not necessary to enter into any more specific description. Two advantages of the arrangement of the two sets of tubes a and a are to be noted. In both externally and internally fired boilers the two sets of tubes are necessarily separated by a space a required by provision in combustion-chamber O at rear of boiler for compelling the fire-gases to enter the lower set of tubes a, this provision consisting in covering said combustion-chamber with fire-brick tile 0, asbestos fire-felt, or similar non-conducting materials 0', and preferably, also, with a metal plate 0 for protecting the asbestos and holding it in place. This space between the tubes tends to equalize and improve circulation in the boiler and affords opportunity for inserting hand-holes in the front head, as a, Fig. III, which is desirable in the case of internally-fired boilers and also in externally-fired boilers where feed-water is of such a nature as to requre frequent and thorough washing of the tubes with a hose.

The discharge of gases and smoke at the rear end of boiler is-generally an ad vantage, as it is usually more convenient to connect with chimney at this end and it removes unsightly smoke connections from the front and gives room for bringing out the steam-discharge pipe at the front.

While the best conditions and results are secured by the arrangement shown and described, it would be possible to otherwise 10- cate the two sets of tubes with respect to each other-as, for instance, side by side-and I therefore do not confine myself strictly to arranging one set of tubes immediately above the other. I

In connection with the boilers having two sets of tubes arranged substantially as shown and described the use of a fan for producing requisite draft enables smaller and shorter tubes to be used and the boiler to be somewhat reduced in size as compared with the proportions required where natural draft is depended upon. This is of most importance in case of internally-fired boilers in respect to reducing the length and cost of internal furnaces.

The sediment-trough G, Figs. I and II, is preferably made of such form and size as to be removable through manhole a for the purpose of cleaning the trough, and to facilitate removal the trough is preferably supported on wheels, as shown. The delivery end of the feed-water pipe is preferably so placed as to deliver feed-water into the trough, so as to deposit contained solid matter therein and to provide for heating the feed-water before mingling with the body of fully-heated water in the boiler.

The flue-door at front end of boiler has a lining of non-conducting material to prevent loss of heat from the gases through transmission of heat through the door, and all steamheated surfaces are covered with non-heat conducting materials.

An essential feature of the construction is the extension of the boiler-shell beyond the tube-plates at both front and rear to form practically air-tight smoke-boxes, as on the matter of tightness depends the capacity and economy of the boiler. As the greatest difficulty in properly proportioning this style of boiler is to get sufficient area in each set of tubes to correspond with the heating surface, it is important that the value of the tube area should not be reduced by any air-leaks at either end of the boiler, and this can only be prevented by making the smoke-box at each end entirely of metal, and a part of boilershell. Without such provision for air-tight smoke-boxes this style of boiler would be practically inoperative.

What I claim as my invention, and desire to secure by Letters Patent, is-- 1. In a horizontal return-tube boiler, a single cylindrical shell, two sets of boiler-tubes through which the products of combustion pass successively, and a smoke-flue'formed in an extension of the said shell beyond the front tube-plate, said extension of the shell being closed by a flue-door so as to render the extension practically an air-tight passage connecting the two sets of boiler-tubes substantially as herein set forth.

2. In a horizontal return-tube boiler, a single cylindrical shell, two sets of boiler-tubes through which the products of combustion pass successively, a smoke-flue formed in an extension of the said shell beyond the front flue-plate, said extension being closed by a flue-door so as to create practically an airtight passage connecting the front ends of the two sets of boiler-tubes, and a smoke-flue inclosing the rear end of the upper set of tubes and a combination-flue inclosing the rear of the lower set of tubes, said rear smokeflue and said combustion-flue being formed in an extension of the cylindrical boiler-shell beyond the rear tube-plate, substantially as herein set forth.

3. In a horizontal return-tube boiler, a single cylindrical shell, two sets of boiler-tubes through which. the products of combustion pass successively, a smoke-flue formed in an extension of the said shell beyond the front flue-plate, said extension being closed by a fine-door so as to create practically an airtight passage connecting the front ends of the two sets of boiler-tubes, a smoke-flue inclosing the rear ends of the upper set of tubes, a combustion-flue inclosing the rear ends of the lower set of tubes, and an exhaust-fan chamber connecting with the said rear smoke= flue, said rear smoke-flue, said rear combustion-flue and said exhaust-fan chamber being all formed in an extension of the cylindrical boiler-shell beyond the rear tube-plate, substantially as herein set forth.

OASSIUS CARROLL PEOK.

WVitnesses:

D. W. GARDNER, FLORENCE MIATT. 

